Conventionally, an annotation technology of providing visual interpretation content to a user by overlay display when the user uses an application has been known. For example, when the annotation technology is applied to real-time video, overlay display of an interpretation result at each moment is performed and updated in synchronization with change or motion as an interpretation target, and the original video and interpretation thereof are simultaneously presented to the user. In this manner, the user can be supported with information by integrally presenting the target and the interpretation to the user without changing the original video.
A specific application in this field is an annotation system (for example, refer to Patent Literature 1). The system continuously captures images of a screen of a PC to search the screen for a region similar to a specified image template, and performs overlay display of an icon at an obtained position.
In this example, a plurality of rules that are each a set of an image template and a short message corresponding thereto are manually defined in advance. Image template matching with these rule sets is performed on a capture image at each moment to calculate a position at which an icon is to be displayed. This processing corresponds to processing of image content interpretation. Annotation to a particular button or a text field on the window of a system AP or addition of hint information to a particular icon or string on each row of a displayed table can be achieved through overlay display of interpretation content on the screen of a PC being operated by a person.